The English Channel’s name in Spanish El Canal de la Mancha, literarily translates as The Channel of the Stain. This is historically an unfortunate translation mistake from its French name Canal de la Manche, which in French means Channel of the Sleeve, yes, as in a shirt. Probably the channel’s shape resembled a sleeve to the French.
The correct Spanish translation would have been Canal de la Manga. Some people
like to think the channel is named after a region in Spain called La Mancha, but this is not the case. By the way, the noun manga in Spanish, which in general means sleeve, has nothing
to do with Japanese comic books.
Originally posted on 20060606. Latest update 20210414 (spanishNY.com)